JP6985957B2 - Semiconductor processing equipment - Google Patents

Description

The present embodiment relates to a semiconductor processing apparatus.

In a semiconductor processing apparatus such as a batch type cleaning apparatus, the chemical solution in the processing tank is circulated in order to keep the concentration of the chemical solution uniform even during the processing of the semiconductor substrate. However, the flow velocity of the chemical solution is high in the vicinity of the nozzle for supplying the chemical solution and becomes slower as the distance from the nozzle is increased. Such variations in the flow velocity of the chemical solution cause variations in the processing speed such as the etching rate on the surface of the semiconductor substrate. Further, in a region where the flow rate of the chemical solution is slow, by-products such as silica may precipitate on the surface of the semiconductor substrate.

Japanese Unexamined Patent Publication No. 2006-108512 Japanese Unexamined Patent Publication No. 10-335295

Provided is a semiconductor processing apparatus capable of substantially making the processing speed on the surface of a semiconductor substrate substantially uniform and suppressing the precipitation of by-products on the surface of the semiconductor substrate.

The semiconductor processing apparatus according to the present embodiment includes a processing tank capable of storing the chemical solution and immersing the semiconductor substrate in the chemical solution. The gas supply unit is provided below the semiconductor substrate housed in the processing tank, and supplies bubbles to the chemical solution from below the semiconductor substrate. The chemical solution supply unit is provided above the gas supply unit and below the semiconductor substrate, and discharges the chemical solution circulated from the treatment tank toward the bubbles appearing from the gas supply unit.

The conceptual diagram which shows the structural example and the operation example of the semiconductor processing apparatus by 1st Embodiment. The figure which shows the arrangement relation of a gas supply pipe and a pair of chemical liquid supply pipes in more detail. The perspective view which shows the structural example of a gas supply pipe and a pair of chemical liquid supply pipes. The flow chart which shows an example of the processing method using the processing apparatus by 1st Embodiment. The conceptual diagram which shows the configuration example and the operation example of the processing apparatus by the modification of 1st Embodiment. The conceptual diagram which shows the configuration example and the operation example of the processing apparatus by 2nd Embodiment. The perspective view which shows the structure of the chemical solution supply pipe in more detail. The graph which shows the relationship between the ratio of the discharge stop period of the chemical liquid C and the precipitation amount of a by-product by 2nd Embodiment. The conceptual diagram which shows the structural example of the processing apparatus 1 by 3rd Embodiment. The graph which shows the swing width and swing speed of a lifter 60. The graph which shows the speed and acceleration of a lifter 60. The figure which shows the cross section after removing the silicon nitride film in the manufacturing of a three-dimensional memory cell array.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings. The present embodiment is not limited to the present invention. The drawings are schematic or conceptual, and the ratio of each part is not always the same as the actual one. In the specification and the drawings, the same elements as those described above with respect to the existing drawings are designated by the same reference numerals, and detailed description thereof will be omitted as appropriate.

(First Embodiment)
1A and 1B are conceptual diagrams showing a configuration example and an operation example of the semiconductor processing apparatus 1 according to the first embodiment. The semiconductor processing apparatus (hereinafter, simply referred to as a processing apparatus) 1 is an apparatus for processing a plurality of semiconductor substrates W by immersing them in a chemical solution C, such as a batch type cleaning apparatus and a wet etching apparatus.

The processing apparatus 1 includes a processing tank 10, gas supply pipes 20a and 20b, chemical liquid supply pipes 30a to 30d, a circulation tank 40, a controller 50, valves V1 and V2, pumps P1 and P2, and piping PP1. It includes PP2, PP10a, PP10b, PP20a to PP20d, and a filter F.

The treatment tank 10 stores the chemical solution C, and can accommodate one or a plurality of semiconductor substrates W in a substantially vertical direction. The semiconductor substrate W is placed on a lifter (see 60 in FIG. 9) so as to lean against it in a substantially vertical direction, and is housed in the processing tank 10 together with the lifter. The semiconductor substrate W is immersed in the chemical solution C by being housed in the processing tank 10.

The gas supply pipes 20a and 20b as the gas supply unit are provided near the bottom of the processing tank 10 and are located below the semiconductor substrate W housed in the processing tank 10. The gas supply pipes 20a and 20b supply bubbles B to the chemical solution C from below the semiconductor substrate W.

The chemical liquid supply pipes 30a to 30d as the chemical liquid supply unit are provided above the gas supply pipes 20a and 20b and below the semiconductor substrate W. The chemical liquid supply pipes 30a to 30d discharge the chemical liquid C toward the bubbles B appearing from the gas supply pipes 20a and 20b. At this time, the chemical solution C is discharged in the direction indicated by the arrow A1 or A2, and bends the moving direction of the bubble B.

The bubble B tends to rise substantially vertically upward in the chemical solution C. However, due to the flow pressure of the chemical solution C from the chemical solution supply pipes 30a to 30d, the bubble B is pushed in the direction of the arrow A1 or A2 and rises while moving.

For example, in FIG. 1A, the chemical liquid supply pipes 30b and 30d discharge the chemical liquid C in the direction of the arrow A1, and the bubble B rises while bending in the direction of the arrow A1. In FIG. 1B, the chemical liquid supply pipes 30a and 30c discharge the chemical liquid C in the direction of the arrow A2, and the bubble B rises while bending in the direction of the arrow A2. In this way, the chemical liquid supply pipes 30a to 30d can control the moving direction of the bubble B to some extent by discharging the chemical liquid C.

The circulation tank 40 stores the chemical solution C overflowing from the treatment tank 10. The chemical solution C in the circulation tank 40 is returned to the treatment tank 10 via the pipes PP1, PP2, pumps P1, P2 and valves V1 and V2. As a result, the chemical solution C is circulated between the treatment tank 10 and the circulation tank 40. The chemical solution C may be filtered by the filter F during circulation.

The circulation tank 40 is connected to the valve V1 via the pipe PP1 and is connected to the valve V2 via the pipe PP2. A pump P1 is provided in the pipe PP1. The pump P1 sends the chemical solution C from the circulation tank 40 to the valve V1. The pipe PP2 is provided with a pump P2. The pump P2 sends the chemical solution C from the circulation tank 40 to the valve V2. The filter F removes impurities mixed in the chemical solution C. The filter F may be provided in the pipes PP1 and PP2, respectively, or may be shared by the pipes PP1 and PP2.

The valve V1 is connected to the gas supply pipe 20a via the pipe PP10a and is connected to the gas supply pipe 20b via the pipe PP10b. The valve V1 mixes a gas with the chemical solution C and supplies the chemical solution C and the gas to the gas supply pipes 20a and 20b substantially evenly. As a result, the gas supply pipes 20a and 20b can discharge almost the same amount of bubbles B. As the gas, for example, an inert gas such as nitrogen is used. For the chemical solution C, for example, a hot phosphoric acid solution is used when removing the silicon nitride film, and a hydrofluoric acid solution is used when removing the silicon oxide film. The chemical solution C can be arbitrarily selected depending on the type of the membrane to be removed, and is not limited thereto.

Further, by adjusting the valve V1, the amount of gas mixed with the chemical solution C can be adjusted. When the amount of bubbles B discharged from the gas supply pipes 20a and 20b is biased, the valve V1 is adjusted to discharge substantially the same amount of bubbles B from the gas supply pipes 20a and 20b. Thereby, the amount and balance of the bubbles B discharged from the gas supply pipes 20a and 20b can be adjusted.

The valves V2 are connected to the chemical liquid supply pipes 30a to 30d via the pipes PP20a to PP20d, respectively. The valve V2 adjusts the amount of the chemical solution C supplied to each of the chemical solution supply pipes 30a to 30d. For example, as shown in FIG. 1A, when the chemical solution C is discharged in the direction of the arrow A1, the valve V2 supplies the chemical solution C to the chemical solution supply pipes 30b and 30d and supplies the chemical solution C to the chemical solution supply pipes 30a and 30c. To stop. As a result, the chemical solution supply pipes 30b and 30d discharge the chemical solution C toward the bubble B. On the other hand, as shown in FIG. 1B, when the chemical solution C is discharged in the direction of the arrow A2, the valve V2 supplies the chemical solution C to the chemical solution supply pipes 30a and 30c and supplies the chemical solution C to the chemical solution supply pipes 30b and 30d. To stop. As a result, the chemical solution supply pipes 30a and 30c discharge the chemical solution C toward the bubble B. By adjusting the valve V2 in this way, the discharge direction of the chemical liquid C discharged from the chemical liquid supply pipes 30a to 30d can be switched. Further, by adjusting the valve V2, the flow velocity or the flow pressure of the chemical liquid C discharged from the chemical liquid supply pipes 30a to 30d can be changed. The flow rate or flow pressure of the chemical solution C may be adjusted by changing the output of the pump P2.

Further, the switching between the state of FIG. 1A and the state of FIG. 1B may be performed instantaneously in a short time. However, in order to improve the uniformity of the surface treatment of the semiconductor substrate W, the state of FIG. 1A and the state of FIG. 1B may be switched over a certain long time. In this case, the controller 50 may gradually change the amount and flow pressure of the chemical liquid C discharged from the chemical liquid supply pipes 30a to 30d by adjusting the valve V2 or the pump P2.

The controller 50 controls the operations of the valves V1 and V2 and the pumps P1 and P2.

As described above, the chemical solution C is not only used for processing the semiconductor substrate W, but is also discharged toward the bubbles B from the gas supply pipes 20a and 20b, and is also used for controlling the moving direction of the bubbles B.

The pair of chemical liquid supply pipes 30a and 30b are provided corresponding to one gas supply pipe 20a. The chemical liquid supply pipes 30a and 30b are arranged at positions substantially symmetrical on both sides above the gas supply pipe 20a. That is, the chemical liquid supply pipe 30a is arranged at a position displaced from directly above the gas supply pipe 20a to one side in the substantially horizontal direction, and the chemical liquid supply pipe 30b is located on the other side in the substantially horizontal direction from directly above the gas supply pipe 20a. It is placed in a position that is offset. In the vertical cross section as shown in FIGS. 1 (A) and 1 (B), the chemical liquid supply pipes 30a and 30b and the gas supply pipe 20a are abbreviated with the straight line connecting the chemical liquid supply pipe 30a and the chemical liquid supply pipe 30b as the base. It is placed at the apex of an isosceles triangle.

Similarly, a pair of chemical solution supply pipes 30c and 30d are provided corresponding to one gas supply pipe 20b. The chemical liquid supply pipes 30c and 30d are arranged at positions substantially symmetrical on both sides above the gas supply pipe 20b. That is, the chemical liquid supply pipe 30c is arranged at a position shifted from directly above the gas supply pipe 20b to one side in the substantially horizontal direction, and the chemical liquid supply pipe 30d is located on the other side in the substantially horizontal direction from directly above the gas supply pipe 20b. It is placed in a position that is offset. In the vertical cross section as shown in FIGS. 1 (A) and 1 (B), the chemical liquid supply pipes 30c and 30d and the gas supply pipe 20b are abbreviated with the straight line connecting the chemical liquid supply pipe 30c and the chemical liquid supply pipe 30d as the base. It is placed at the apex of an isosceles triangle.

In this embodiment, two sets of the gas supply pipe and the pair of chemical liquid supply pipes are provided. However, this combination may be provided only once or may be provided in three or more.

2 (A) and 2 (B) are views showing in more detail the arrangement relationship between the gas supply pipe 20a and the pair of chemical solution supply pipes 30a and 30b. Here, the arrangement relation of the chemical liquid supply pipes 30c and 30d and the gas supply pipe 20b may be the same as the arrangement relation of the chemical liquid supply pipes 30a and 30b and the gas supply pipe 20a.

The chemical liquid supply pipes 30a and 30b are arranged so as to be substantially horizontal from directly above the gas supply pipe 20a, and the chemical liquid C is discharged in the substantially horizontal direction (arrow A30_1) or the inclined direction (arrow A30_1) toward the bubble B. do. As a result, as shown by the arrow A20, the bubble B rises while being bent in the discharge direction of the chemical liquid C (arrows A30_1, A30_2) from directly above the gas supply pipe 20a.

FIG. 3 is a perspective view showing a configuration example of the gas supply pipe 20a and the pair of chemical solution supply pipes 30a and 30b. Since the configurations of the gas supply pipe 20b and the chemical liquid supply pipes 30c and 30d may be the same as the configurations of the gas supply pipe 20a and the chemical liquid supply pipes 30a and 30b, the illustration thereof will be omitted.

The gas supply pipe 20a is a pipe extending in the arrangement direction D1 of the plurality of semiconductor substrates W. Further, the gas supply pipe 20a has a hole H20a provided toward the upper side D2. The bubble B is supplied from the hole H20a toward the semiconductor substrate W located above D2.

The chemical solution supply pipes 30a and 30b are pipes extending in the arrangement direction D1 of the plurality of semiconductor substrates W. Further, the chemical liquid supply pipes 30a and 30b have holes H30a and H30b that open diagonally upward from the substantially horizontal direction D3 or the horizontal direction D3. As a result, the chemical liquid supply pipes 30a and 30b discharge the chemical liquid C toward the bubbles B from the gas supply pipe 20a.

Here, the chemical liquid supply pipes 30a and 30b alternately discharge the chemical liquid C. That is, the state of FIG. 2 (A) and the state shown in FIG. 2 (B) are alternately repeated. As a result, the bubble B can be swung in the substantially horizontal direction D3 and applied to the entire surface of the semiconductor substrate W.

If the bubbles B hit only locally on the surface of the semiconductor substrate W, the flow velocity of the chemical solution C varies on the surface of the semiconductor substrate W, and the processing speed (for example, etching rate) also varies on the surface of the semiconductor substrate W. In this case, the surface of the semiconductor substrate W may be locally excessively processed, or conversely, the processing may be insufficient. Further, if the flow velocity of the chemical solution C varies on the surface of the semiconductor substrate W, by-products (for example, silica) are deposited on the surface of the semiconductor substrate W at the place where the flow velocity of the chemical solution C is slow.

On the other hand, in the processing apparatus 1 according to the present embodiment, since the bubbles B can be applied to the entire surface of the semiconductor substrate W, the processing speed of the entire surface of the semiconductor substrate W can be made substantially uniform. As a result, the processing speed on the surface of the semiconductor substrate W can be substantially made uniform, and the precipitation of by-products on the surface of the semiconductor substrate W can be suppressed.

In the chemical solution supply pipes 30a and 30b, the cycle for discharging the chemical solution C is not particularly limited. However, in order to apply the bubbles B to the surface of the semiconductor substrate W substantially uniformly, it is preferable that the discharge period of the chemical liquid supply pipe 30a and the discharge period of the chemical liquid supply pipe 30b are substantially the same.

In FIG. 3, the gas supply pipes 20a and 20b and the chemical liquid supply pipes 30a to 30d are pipes having a circular cross section. However, the cross-sectional shapes of the gas supply pipes 20a and 20b and the chemical liquid supply pipes 30a to 30d are not limited to this, and may be elliptical, polygonal, or the like. Further, the shapes of the holes H20a, H30a, and H30b may be circular, elliptical, or polygonal.

Next, the operation of the processing device 1 will be described.

FIG. 4 is a flow chart showing an example of a processing method using the processing apparatus 1 according to the first embodiment. It is assumed that the treatment tank 10 stores the chemical solution C.

First, the semiconductor substrate W is mounted on the lifter, the semiconductor substrate W is put into the processing tank 10, and the semiconductor substrate W is immersed in the chemical solution C (S10).

Next, the controller 50 controls the valves V1 and V2 and the pumps P1 and P2 to start discharging the bubbles B and the chemical solution C. At this time, the gas supply pipes 20a and 20b each supply the bubbles B to the upper semiconductor substrate W. The chemical liquid supply pipes 30a and 30b alternately and periodically discharge the chemical liquid C. The chemical liquid supply pipes 30c and 30d also periodically discharge the chemical liquid C alternately (S20). As a result, the bubble B moves upward while swinging in a substantially horizontal direction.

Step S20 is continued until a predetermined time elapses (NO in S30).

When the predetermined time elapses (YES in S30), the lifter pulls up the semiconductor substrate W from the processing tank 10 (S40). This ends a series of processes.

As described above, the processing apparatus 1 according to the present embodiment can swing the bubble B by discharging the chemical solution C into the bubble B, and can apply the bubble B to the entire surface of the semiconductor substrate W substantially uniformly. As a result, the processing speed on the surface of the semiconductor substrate W can be substantially made uniform, and the precipitation of by-products on the surface of the semiconductor substrate W can be suppressed.

(Modification example)
5 (A) and 5 (B) are conceptual diagrams showing a configuration example and an operation example of the processing device 1 according to the modified example of the first embodiment. The processing apparatus 1 according to this modification is different from the first embodiment in that one chemical solution supply pipe is provided for each of the gas supply pipes 20a and 20b. For example, in the examples shown in FIGS. 5 (A) and 5 (B), the chemical liquid supply pipe 30b is provided for the gas supply pipe 20a, and the chemical liquid supply pipe 30c is provided for the gas supply pipe 20b. There is. Therefore, the chemical liquid supply pipes 30a and 30d and the pipes PP20a and PP20d are not provided.

The chemical solution supply pipe 30b is offset to one side above the gas supply pipe 20a, and the chemical solution supply pipe 30c is offset to one side above the gas supply pipe 20b. The arrangement relationship between the chemical solution supply pipe 30b and the gas supply pipe 20a and the arrangement relationship between the chemical solution supply pipe 30c and the gas supply pipe 20b may be the same as those in the first embodiment.

Further, the chemical solution supply pipes 30b and 30c alternately and periodically periodically discharge the chemical solution C into the bubble B. For example, as shown in FIG. 5A, when the chemical liquid supply pipe 30b discharges the chemical liquid C in the direction of the arrow A1, the chemical liquid supply pipe 30c stops the discharge of the chemical liquid C. Therefore, the bubble B from the gas supply pipe 20a is bent in the direction of the arrow A1, but the bubble B from the gas supply pipe 20b is not bent so much. On the other hand, as shown in FIG. 5B, when the chemical liquid supply pipe 30c discharges the chemical liquid C in the direction of the arrow A2, the chemical liquid supply pipe 30b stops the discharge of the chemical liquid C. Therefore, the bubble B from the gas supply pipe 20b is bent in the direction of the arrow A2, but the bubble B from the gas supply pipe 20a is not bent so much.

In this way, the chemical solution supply pipes 30b and 30c alternately discharge the chemical solution C. That is, the state of FIG. 5A and the state shown in FIG. 5B are alternately repeated. Even in this way, the bubbles B can be swung in a substantially horizontal direction, and the variation in the processing speed on the surface of the semiconductor substrate W can be alleviated to some extent.

Alternatively, the chemical solution supply pipes 30b and 30c may periodically discharge the chemical solution C to the bubble B at the same time. For example, at the same time that the chemical solution supply pipe 30b discharges the chemical solution C in the direction of the arrow A1, the chemical solution supply pipe 30c also discharges the chemical solution C in the direction of the arrow A2. In this case, the bubble B from the gas supply pipe 20a is bent in the direction of arrow A1, and the bubble B from the gas supply pipe 20b is bent in the direction of arrow A2. On the other hand, when the chemical liquid supply pipe 30b stops the discharge of the chemical liquid C, the chemical liquid supply pipe 30c also stops the discharge of the chemical liquid C. Therefore, the bubbles B from the gas supply pipe 20a and the gas supply pipe 20b rise substantially vertically upward.

In this way, the chemical liquid supply pipes 30b and 30c may simultaneously discharge the chemical liquid C. Even in this way, the bubbles B can be swung in a substantially horizontal direction, and the variation in the processing speed on the surface of the semiconductor substrate W can be alleviated to some extent.

(Second Embodiment)
6 (A) and 6 (B) are conceptual diagrams showing a configuration example and an operation example of the processing apparatus 1 according to the second embodiment. In the first embodiment, the moving direction of the bubble B is swung by the chemical solution C from the chemical solution supply pipes 30a to 30d, and the flow velocity of the chemical solution C on the surface of the semiconductor substrate W is substantially made uniform by the bubble B. On the other hand, in the processing apparatus 1 according to the second embodiment, the flow velocity of the chemical solution C on the surface of the semiconductor substrate W is substantially made uniform by the chemical solution C from the chemical solution supply pipes 30a and 30b without using the bubble B. Therefore, the processing apparatus 1 according to the second embodiment includes the chemical liquid supply pipes 30a and 30b, but does not have the gas supply pipes 20a and 20b.

The circulation tank 40, the pipe PP1, the pump P1, and the filter F may have the same configurations as those of the first embodiment.

The valve V1 is connected to the chemical liquid supply pipe 30a via the pipe PP10a, and is connected to the chemical liquid supply pipe 30b via the pipe PP10b. The valve V1 supplies the chemical solution C to the chemical solution supply pipes 30a and 30b substantially evenly. The valve V1 according to the second embodiment does not mix the gas with the chemical solution C. As a result, the chemical solution supply pipes 30a and 30b discharge almost the same amount of the chemical solution C. When the amount of the chemical liquid C discharged from the chemical liquid supply pipes 30a and 30b is biased, the valve V1 can be adjusted to discharge substantially the same amount of the chemical liquid C from the chemical liquid supply pipes 30a and 30b.

The pair of chemical solution supply pipes 30a and 30b are arranged at positions substantially symmetrical on both sides below the semiconductor substrate W. The chemical liquid supply pipes 30a and 30b discharge the chemical liquid C from diagonally below the semiconductor substrate W immersed in the chemical liquid C toward the semiconductor substrate W.

FIG. 7 is a perspective view showing the configuration of the chemical liquid supply pipes 30a and 30b in more detail. The chemical solution supply pipes 30a and 30b have holes H30a and H30b that open toward the center of the semiconductor substrate W or the processing tank 10, respectively. In other words, the holes H30a and H30b are opened in the Da direction and the Db direction inclined from the vertical direction D2 to the side facing each other (opposing direction), respectively. As a result, the chemical liquid supply pipes 30a and 30b can discharge the chemical liquid C toward the center of the semiconductor substrate W.

In the second embodiment, the controller 50 controls the valve V1 so that the chemical liquid C is alternately discharged from the pair of chemical liquid supply pipes 30a and 30b to the semiconductor substrate W. That is, the state shown in FIG. 6 (A) and the state shown in FIG. 6 (B) are alternately repeated. In this case, since one of the chemical solution supply pipes 30a and 30b discharges the chemical solution C in the short term, the flow velocity of the chemical solution C on the surface of the semiconductor substrate W is locally different. However, when the treatment as a whole is averaged over a long period of time, the flow velocity of the chemical solution C can be made uniform on the surface of the semiconductor substrate W.

For example, if both the chemical liquid supply pipes 30a and 30b simultaneously discharge the chemical liquid C, the flow of the chemical liquid C from the chemical liquid supply pipe 30a and the flow of the chemical liquid C from the chemical liquid supply pipe 30b are near the center of the semiconductor substrate W. Collide with each other and cancel each other out. Therefore, the flow velocity of the chemical solution C is relatively fast up to the center of the semiconductor substrate W, but slows down at the upper part of the semiconductor substrate W. This deteriorates the in-plane uniformity of the treatment.

Further, since the chemical liquid supply pipes 30a and 30b continuously discharge the chemical liquid C, the flow velocity of the chemical liquid C is high in the vicinity of the chemical liquid supply pipes 30a and 30b. Therefore, in the region of the surface of the semiconductor substrate W near the chemical solution supply pipes 30a and 30b, the processing can easily proceed. Therefore, the in-plane uniformity of the treatment is further deteriorated.

On the other hand, in the second embodiment, the chemical liquid supply pipes 30a and 30b alternately discharge the chemical liquid C to the semiconductor substrate W. In this case, one of the flow of the drug solution C from the drug solution supply pipe 30a and the flow of the drug solution C from the drug solution supply pipe 30b does not affect the other and does not obstruct the flow. Therefore, the flow velocity of the chemical solution C reaches from the center of the semiconductor substrate W to the tip thereof, and the difference between the flow velocity at the lower part and the flow velocity at the upper part of the semiconductor substrate W becomes small. This makes it possible to improve the in-plane uniformity of the treatment.

Further, the chemical solution supply pipes 30a and 30b alternately and periodically discharge the chemical solution C. Therefore, although the flow velocity of the chemical solution C becomes intermittently high in the vicinity of the chemical solution supply pipes 30a and 30b, the average flow velocity of the chemical solution C approaches uniformly on the surface of the semiconductor substrate W as a whole. Therefore, the in-plane uniformity of the treatment can be further improved. Therefore, the second embodiment can obtain the same effect as the first embodiment.

The switching between the state of FIG. 6A and the state of FIG. 6B may be performed instantaneously in a short time. However, in order to improve the uniformity of the surface treatment of the semiconductor substrate W, the state of FIG. 6A and the state of FIG. 6B may be switched over a certain long time. In this case, the controller 50 may gradually change the amount and the flow velocity of the chemical liquid C discharged from the chemical liquid supply pipes 30a and 30b by adjusting the valve V1 or the pump P1.

(Discharge period and discharge stop period of chemical solution C)
FIG. 8 is a graph showing the relationship between the ratio of the discharge stop period of the chemical solution C and the precipitation amount of the by-product according to the second embodiment. The vertical axis of this graph shows, for example, the amount of _{silica (SiO 2) deposited as a by-product.} The horizontal axis shows the ratio of the period during which the chemical liquid supply pipes 30a and 30b stop discharging the chemical liquid C during the treatment. For example, it is assumed that the chemical liquid supply pipes 30a and 30b each discharge the chemical liquid C at a certain discharge cycle. Further, the discharge period in which the chemical liquid supply pipes 30a and 30b are discharging the chemical liquid C is defined as Ton, and the discharge stop period in which the discharge of the chemical liquid C is stopped is defined as Toff. In this case, the discharge cycle is the sum of the discharge period Ton and the discharge stop period Tof (Ton + Toff). The horizontal axis shows the ratio (Toff / (Ton + Toff)) of the discharge stop period Toff to one discharge cycle (Ton + Toff).

According to FIG. 8, it can be seen that when the ratio (Toff / (Ton + Toff)) decreases, the amount of silica precipitated increases. For example, a NAND EEPROM (Electrically Erasable Programmable Read-Only Memory) may have a three-dimensional memo cell array in which memory cells are three-dimensionally arranged. In this case, a groove TR is formed in the stacking direction of the laminated body of the silicon oxide film and the silicon oxide film, and the silicon nitride film of the laminated body is replaced with a metal. It is necessary to temporarily remove the silicon nitride film in the lateral direction (perpendicular to the stacking direction) via the groove TR. For example, FIG. 12 is a diagram showing a cross section after removing the silicon nitride film in the manufacture of a three-dimensional memory cell array. After the removal of the silicon nitride film, a gap G extending laterally is formed between the layers of the silicon oxide film 101, but since the by-product SP is deposited at the end of the silicon oxide film 101, the gap G is formed in the vicinity of the groove TR. It gets narrower. The precipitation amount of the by-product shown in FIG. 8 is the film thickness TH in the stacking direction of the by-product SP deposited on the silicon oxide film 101. That is, the amount of the by-product SP deposited is about half the difference between the width of the void G in the stacking direction in the vicinity of the groove TR and the width of the void G in the stacking direction at a location away from the groove TR. The amount of the by-product SP deposited is preferably about 3 nm or less. Precipitation of many by-products SP leads to open or short defects in wiring (eg, word wires, etc.). Therefore, in the above example, the precipitation amount of the by-product SP is preferably about 3 nm or less. In this case, the ratio (Toff / (Ton + Toff)) is 0.765 or more. That is, in one discharge cycle (Ton + Toff), the ratio of the discharge stop period Toff of the chemical liquid supply pipes 30a and 30b is 0.765 or more, and the ratio of the discharge period Ton of the chemical liquid supply pipes 30a and 30b is 0.235 or less. Is preferable. However, the amount of by-products deposited increases in proportion to the length of the discharge stop period Toff. Therefore, the lower limit of the ratio of the discharge stop period Tof is set based on the processing time.
As described above, by setting the ratio of the discharge stop period (Toff / (Ton + Toff)) to the discharge cycle of the chemical liquid supply pipes 30a and 30b to 0.765 or more, the in-plane uniformity of the processing of the semiconductor substrate W is improved. Moreover, the precipitation of by-products can be suppressed.

The graph of FIG. 8 can also be applied to a modified example of the first embodiment. That is, when the chemical liquid supply pipes 30b and 30c alternately or simultaneously discharge the chemical liquid C, the period during which the chemical liquid supply pipes 30b and 30c discharge the chemical liquid C is set as the discharge period Ton, and the chemical liquid supply pipes 30b and 30c discharge the chemical liquid C. The ratio (Toff / (Ton + Toff)) is preferably 0.765 or more when the period for stopping is set to the discharge stop period Tof. By setting the discharge period Ton and the discharge stop period Toff in this way, it is possible to improve the in-plane uniformity of the treatment of the semiconductor substrate W and suppress the precipitation of by-products even in the above-mentioned modification. can.

(Third Embodiment)
FIG. 9 is a conceptual diagram showing a configuration example of the processing device 1 according to the third embodiment. In the third embodiment, the lifter 60 swings the semiconductor substrate W in the processing tank 10 in a substantially vertical direction. This reduces the variation in the flow velocity of the chemical solution C on the surface of the semiconductor substrate W.

The processing apparatus 1 according to the third embodiment includes a lifter 60 on which the semiconductor substrate W can be placed so as to lean against it in a substantially vertical direction. The semiconductor substrate W can be housed in the processing tank 10 in a state of being placed on the lifter 60, and the semiconductor substrate W can be immersed in the chemical solution C. The lifter 60 as a mounting portion is connected to the lifter support portion 70 and can move in the substantially vertical direction D2 together with the lifter support portion 70.

The drive unit 80 can move the lifter 60 together with the lifter support unit 70 in the substantially vertical direction D2. The drive unit 80 is controlled by the controller 50.

The controller 50 reciprocates (sways) the lifter 60 at a speed and acceleration such that the flow velocity of the chemical solution C with respect to the surface of the semiconductor substrate W is equal to or higher than a predetermined threshold value (first threshold value) and the semiconductor substrate W does not float from the lifter 60. Move).

By swinging the semiconductor substrate W in the chemical solution C, the surface of the semiconductor substrate W is moved relative to the chemical solution C. As a result, the chemical solution C is in the same state as flowing on the surface of the semiconductor substrate W. Since the flow of the chemical solution C with respect to the semiconductor substrate W occurs on the entire surface of the semiconductor substrate W, the variation in the flow velocity of the chemical solution C on the surface of the semiconductor substrate W is reduced.

The calculation unit 90 calculates the speed and acceleration so that the flow velocity of the chemical solution C with respect to the surface of the semiconductor substrate W becomes a predetermined threshold value (first threshold value) or more and the semiconductor substrate W does not float from the lifter 60.

Other configurations of the third embodiment may be the same as the corresponding configurations of the first embodiment. The third embodiment may not include the gas supply pipe and the chemical solution supply pipe. Further, the third embodiment may be combined with a modified example of the first embodiment or the second embodiment. Thereby, the third embodiment can obtain the same effect as the first embodiment, the modified example, or the second embodiment.

(Rifter speed and acceleration)
FIG. 10 is a graph showing the swing width and swing speed of the lifter 60. The vertical axis of this graph shows the speed of the reciprocating motion of the lifter 60. The horizontal axis indicates the reciprocating width of the lifter 60. The speed is the maximum speed of the lifter 60 when the lifter 60 is reciprocated in a substantially vertical direction. The reciprocating width is the movement width (swing width) of the reciprocating motion of the lifter 60.

Further, the line L1 shows the reciprocating width and the speed required to make the flow velocity (relative flow velocity) of the chemical solution C with respect to the surface of the semiconductor substrate W 0.07 m / s. Line L2 shows the reciprocating width and velocity required to bring the relative flow velocity of the chemical solution C to the surface of the semiconductor substrate W to 0.1 m / s. With reference to the lines L1 and L2, it can be seen that when the reciprocating width is reduced, the speed of the lifter 60 needs to be increased in order to maintain the relative flow velocity of the chemical solution C.

Here, in order to suppress the precipitation of by-products, it is known that the relative flow velocity of the chemical solution C on the surface of the semiconductor substrate W is preferably 0.1 m / s or more. Therefore, the threshold value (first threshold value) of the relative flow velocity of the chemical solution C is set to 0.1 m / s, and the line L2 is referred to. When the reciprocating width of the semiconductor substrate W in the reciprocating motion is x, the speed in the reciprocating motion of the semiconductor substrate W is y, and the acceleration in the reciprocating motion of the semiconductor substrate W is z, the line L2 is approximately y =. It is expressed as 2.8 × x ^−0.13. Therefore, in order for the relative flow velocity of the chemical solution C on the surface of the semiconductor substrate W to be 0.1 m / s or more, it is necessary to satisfy Equation 1.
y> 2.8 × x ^−0.13 (Equation 1)

FIG. 11 is a graph showing the speed and acceleration of the lifter 60. The vertical axis of this graph shows the acceleration in the reciprocating motion of the lifter 60. The horizontal axis indicates the speed in the reciprocating motion of the lifter 60. The line L3 indicates a boundary indicating a region R1 in which the semiconductor substrate W does not float from the lifter 60. Therefore, in the region R1 of the graph, the lifter 60 can reciprocate the semiconductor substrate W without floating it. On the other hand, in the region R2, since the semiconductor substrate W floats due to the reciprocating motion, the lifter 60 cannot make the semiconductor substrate W follow the reciprocating motion. Further, if the semiconductor substrate W floats from the lifter 60, the semiconductor substrate W may fall off from the lifter 60.

Here, the line L3 is approximately represented as z = −38.8 × y ² + 3.9 × y + 8.8. Therefore, the area R1 of the graph needs to satisfy Equation 2.
z <-38.8 × y ² +3.9 × y +8.8 (Equation 2)

If the reciprocating width x is set, the velocity y for setting the relative flow velocity of the chemical solution C to 0.1 m / s or more is calculated based on Equation 1. Further, using Equation 2, the acceleration z capable of reciprocating motion without floating the semiconductor substrate W is calculated.

The calculation unit 90 calculates the velocity y and the acceleration z from the reciprocating width x using the equations 1 and 2. The reciprocating width x may be input by the user from the outside, or may be stored in the memory 91 in advance. For example, when the reciprocating width x is 30 mm, the velocity y is calculated from Equation 1 to be about 0.18 m / s or more. Further, the acceleration z is calculated from Equation 2 to be about 8 m / s ² or less.

The controller 50 controls the drive unit 80 so as to reciprocate the semiconductor substrate W with the reciprocating width x according to the calculated speed y and the acceleration z. As a result, the lifter 60 can improve the in-plane uniformity of the flow velocity of the chemical solution C while keeping the flow velocity of the chemical solution C on the surface of the semiconductor substrate W at 0.1 m / s or more. As a result, the in-plane uniformity of the treatment of the semiconductor substrate W can be improved and the precipitation of by-products can be suppressed.

The controller 50 may alternately repeat the execution of the reciprocating motion of the semiconductor substrate W and the stop of the reciprocating motion. Even in this way, the processing apparatus 1 can improve the in-plane uniformity of the processing of the semiconductor substrate W to some extent and suppress the precipitation of by-products.

Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and variations thereof are included in the scope of the invention described in the claims and the equivalent scope thereof, as are included in the scope and gist of the invention.

1 processing device, 10 processing tanks, 20a, 20b gas supply pipes, 30a to 30d chemical supply pipes, 40 circulation tanks, 50 controllers, 60 lifters, 70 lifter supports, 80 drive units, 90 calculation units, V1, V2 valves, P1, P2 pump, PP1, PP2, PP10a, PP10b, PP20a to 20d piping, F filter, H20a, H30a, H30b hole, B bubble, C chemical solution, W semiconductor substrate

Claims (6)

A treatment tank that can store the chemical solution and immerse the semiconductor substrate in the chemical solution,
A gas supply unit provided below the semiconductor substrate housed in the processing tank and supplying bubbles to the chemical solution from below the semiconductor substrate.
The chemical solution circulated from the treatment tank is discharged from the processing tank toward the bubbles appearing from the gas supply section and above the gas supply section and below the semiconductor substrate in order to control the moving direction of the bubbles. A semiconductor processing device equipped with a chemical supply unit. The semiconductor processing apparatus according to claim 1, wherein the chemical solution supply unit is arranged so as to be displaced from directly above the gas supply unit in a substantially horizontal direction, and discharges the chemical solution to the bubbles from a substantially horizontal direction or an inclined direction. A pair of the chemical supply units are arranged on both sides above the gas supply unit at substantially symmetrical positions.
The semiconductor processing apparatus according to claim 2, wherein the pair of chemical liquid supply units alternately discharge the chemical liquid. One of the chemical supply units is offset to one side above the one of the gas supply units.
The semiconductor processing apparatus according to claim 2, wherein the chemical solution supply unit periodically discharges the chemical solution into the bubbles. The discharge stop period in which the chemical supply unit to stop the discharge of the chemical and Toff, a discharge period in which the chemical supply unit to discharge the liquid medicine when the Ton, the discharge period and the at some the chemical supply unit The semiconductor processing apparatus according to claim 4, wherein the ratio of the discharge stop period to the discharge stop period, Toff / (Ton + Toff), is 0.765 or more. A treatment tank that can store the chemical solution and immerse the semiconductor substrate in the chemical solution,
A pair of chemical liquid supply units arranged at substantially symmetrical positions on both lower sides of the semiconductor substrate, and discharge the chemical liquid toward the semiconductor substrate from diagonally below the semiconductor substrate immersed in the chemical liquid. With a pair of chemical supply units,
The pair of chemical solution supply units alternately discharge the chemical solution to the semiconductor substrate.
The discharge stop period in which the chemical supply unit to stop the discharge of the chemical and Toff, a discharge period in which the chemical supply unit to discharge the liquid medicine when the Ton, the discharge period and the at some the chemical supply unit A semiconductor processing apparatus having a Toff / (Ton + Toff) ratio of the discharge stop period to the discharge stop period of 0.765 or more.

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